Apparatus for receiving radiosignals



R. A. WEAGANT.

APPARATUS FOR RECEIVINGRADIOSIGNALS.

APPLICATION FILED DEC.13, I917.

Patentfi Aug. 8, 1922.

TO DETECTOR l/VI/E/l/TOR a. M

onirensrnres arana oaenca ROY A. WEAGANT, OF NEW YORK, Y., ASSIGNOR, BYMESN'E ASSIGNMENTS, TO JRADIO CORPORATION OF AMERICA, A CORPORATION OFDELAWARE,

APPARATUS FOR RECEIVING RADIOSIGNALS.

amet.

Specification of Letters Patent.

llatentcd Aug. 8., 11922.,

Application filed December 13, 1917. Serial No. :aoeeea To all whom itmay concern:

Be it known that I, Roy ALEXANDER NEAGANT, a citizen of the UnitedStates, residing at Douglas Manor, c ounty oi Queens, city and State ofNew York, have discovered certain new and useful Improvements inApparatus for Receiving Radiosignals, of which the following is a spec1fication,

My invention relates to the art of radio signaling and has as itsprincipal ob ect the provision of novel and improved receiving apparatusfor reducing or preventing static interference.

My present invention is based upon observations made by me and setout-at some length in my prior application No. 157,594. wherein I havestated that the so-called static disturbances act as though suchdisturbances were caused by electro-magnet1c waves or impulsespropagated perpendicularly to the surface of the earth, and almostwithout horizontal components. Whether or not this isacorrect statementof the facts, I find that by proceeding on this assumption and byscreening an aerial collector as by placing such collector beneath ametallic or other conducting screen. I am able to very largely overcomethe interference with the reception of radio signals caused by the mostobjectionable forms of atmospheric disturbances, the static Waves beingabsorbed by the screen and the collector consequently shieldedtherefrom. 0n the other hand, commercial radio signal waves travelhorizontally or have a large horizontal component of motion, so that byleaving the collector unscreened on the side from which the signal wavesapproach the receiving station there is practically no change in theefiect of the signal waves on the receiving apparatus. I have found,moreover, in practicing this invention that the efiectiveness of thescreen in absorbing and preventing the passage of static waves isincreased if the screen is grounded. Experience shows also thatgrounding the screen does not decrease the efiect of the signal waves onthe recelving apparatus. This is in accordance with my observations tothe effect that commercial signal Waves extend a material distancebeneath the surface of the ground with small diminution in strength.This fact is set out also in my application for apparatus for preventingstatic interference in radio signaling, Serial Number 206,724, filedDecember 12, 1917.

In the drawing accompanying and forming a part of this specification,Figure l is a diagrammatic perspective view of anapparatus embodying oneform of my invention, and Figure 2 is a similar view of a modification.

Referring more particularly to the draw ing, 11 are posts of anyconvenient height provided with guy wires such as 2. On the upper endsof the posts 1 are supported in any convenient manner conductingcrossbars such as 3, between which are supported a number of conductingor metallic elements such as 5, forming a screen against the verticallymoving component of electromagnetic waves or those which act as ifpropagated in a vertical direction. The members 5 are shown in the formof parallel wires, but it will be understood that this is not essential.The cross-bars 3 are shown as grounded by means of ground wires such as6.

Beneath the screen 5 I have shown a nonconducting frame such as 7, whichmay be supported in a substantially vertical position in any convenientmanner as by guy wlres such as 8. Suspended within the frame 7 by anyconvenient means such as the wires 9, is a loop or coil collector 10arranged substantially in the plane of the frame 7, the collector beinginsulated from the ground. Preferably the horizontal projection of saidscreen overlaps and extends beyond the horizontal projection of thecollector on all sides. The ends of collector 10 are connected to acoupling coil 11. A coil 12 is associated with coil 11 in the usualmanner to impress the received impulses upon a local circuit 13containing a vacuum valve detector 16. Such detector 16 is well known,but is described below in some detail as a matter of convenience. Asshown, the circuit 13 comprises a variable condenser 14 in parallel withthe wires of the circuit 18, a condenser 15 in series with the coil 12.the capacity 15 being connected to the grid of the vacuum valve detector16. -A local heating battery for the filament of the detector is shownat 17, the plate or cold electrode of the valve detector being shown at1.8. The battery 19 is connected with the coil 12 through the plate andfilament of the detector in the usual manner, a telephone 20 being shownin series with the battery 19 and a variable condenser 21 in shuntwiththe telephone 20. An inductance 22 and capacity 23 are connected inparallel to the batter 19 and telephone 20. I

In ig. 2 I have shown a modified form of screen composed of threeconducting plates such as 25, arranged in the form of an inverted troughwith open ends and supported on insulating structures,- such as 26.@onnectecL to the middle of the lower edge of each of the verticalplates 25 is a grounded circuit comprising a variable inductance 27 andvariable capacity 28, whereby the relation of the currents in the screenmay be maintained symmetrical in all respects with relation to anyantenna or collector beneath the screen, so that the currents in thescreen may not of themselves affect the collector. The detector andindicator circuits associated with the collector shown. in Fig. .2 maybe the same as those shown in Fig. 1.

While I have herein specifically illustrated and described only a loopantenna, this particular form is in no wise essential to the practice ofmy invention which my experiments show can be practised with any of theforms of antennae now in commercial combination with a. collector of anopen ended inverted trough-shaped screen covering' said .collector aboveand on two sides, and adjustable grounded circuits connected to thelower edges of said screen at the midpoints thereof.

ROY A. WEAGANT.

